This invention relates to a document processing apparatus and method for a structured document formed by grouping original pages. The document processing apparatus according to this invention controls display of the image objects of either or both of a document structure and an original page contained in the document. The document processing apparatus includes an editor which edits the document so as to insert a new group containing a designated original page to a designated position in accordance with designation of the original page and the position on the displayed image objects. Display of the image objects is controlled for the document edited by the editor.